Blends of ABS and polycarbonate resins were disclosed in U.S. Pat. Nos. 3,130,177 and 3,852,393 and although found suitable for many end uses, the level of impact resistance presented a drawback for some important markets. Similar blends are disclosed in British Pat. No. 1,253,226 whereas U.S. Pat. No. 3,162,695 is noted for its teaching respecting a blend of polycarbonate and a graft copolymer of methylmethacrylate and styrene monomers polymerized in the presence of a butadiene styrene latex. Copolymers of maleic anhydride and .alpha.-olefin have been disclosed as impact modifiers of glass reinforced polycarbonates in copending application Ser. No. 258,817, filed Apr. 29, 1981, now U.S. Pat. No. 4,420,584. The art is further noted to include U.S. Pat. No. 3,966,842 directed to compositions comprising polycarbonate and a diene rubber-containing styrene/maleic anhydride.
Also of interest, the art is noted to include U.S. Pat. Nos. 4,172,103 and 3,880,783, both describing mixtures of special polycarbonates with other thermoplastic resins which later include copolymers of maleic acid anhydride. Also, U.S. Pat. No. 4,205,141, which discloses mixtures of polycarbonates with copolymers from styrene acrylonitrile and maleic acid anhydride, and U.S. Pat. No. 4,204,047, which discloses mixtures of polycarbonates with ABS which may optionally contain an N-substituted maleic imide and with a copolymer which has copolymerized an N-substituted maleic imide, as well as U.S. Pat. No. 3,951,903 which describes the addition to polycarbonate resin of acid anhydrides and optionally glass fibers and U.S. Pat. No. 4,122,130, which discloses a blend of polycarbonate and the imido derivative of rubber-modified styrene maleic anhydride.